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A method for glycogen determination in whole yeast cells

1978; Elsevier BV; Volume: 86; Issue: 1 Linguagem: Inglês

10.1016/0003-2697(78)90318-4

1096-0309

Jörn Ullrich Becker,

Enzyme Catalysis and Immobilization

A method for enzymatic glycogen determination in yeast cells without need for prior disruption of the cell walls has been developed: After stopping cell metabolism with 5% trichloroacetic acid, the cells were digested with 0.25 m Na2CO3 for 90 min on a boiling water bath and pH was adjusted to 4.8. Glycogen was hydrolyzed by amyloglucosidase (E.C. 3.2.1.3) to glucose, then assayed enzymatically. Hydrolysis was quantitative by the following criteria: (i) Glucose production from the cell residues ceased despite the enzyme still being active, (ii) amyloglucosidase-incubated cell residues lost the iodine staining power, and (iii) no glycogen could be extracted after disruption of the cell walls. (iv) α-Amylase was unable to liberate reducing sugars from amyloglucosidase-incubated cell residues and vice versa. The method has been successfully tested with several strains of Saccharomyees cerevisiae and S. carlsbergensis.